From: Josephine Pfeiffer <hi@josie.lol>
Date: Wed, 1 Oct 2025 16:36:22 +0000 (+0200)
Subject: s390/cmm: Replace sprintf() with scnprintf() for buffer safety
X-Git-Tag: v6.19-rc1~206^2~45
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dd7d1d34ae484ba2caed8e01e03bdc4c263b1442;p=thirdparty%2Flinux.git

s390/cmm: Replace sprintf() with scnprintf() for buffer safety

Replace sprintf() with scnprintf() in cmm_timeout_handler() to prevent
potential buffer overflow. The scnprintf() function ensures we don't
write beyond the buffer size and provides safer string formatting.

Signed-off-by: Josephine Pfeiffer <hi@josie.lol>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
---

diff --git a/arch/s390/mm/cmm.c b/arch/s390/mm/cmm.c
index e2a6eb92420fc..eb7ef63fab1e5 100644
--- a/arch/s390/mm/cmm.c
+++ b/arch/s390/mm/cmm.c
@@ -321,8 +321,8 @@ static int cmm_timeout_handler(const struct ctl_table *ctl, int write,
 		cmm_set_timeout(nr, seconds);
 		*ppos += *lenp;
 	} else {
-		len = sprintf(buf, "%ld %ld\n",
-			      cmm_timeout_pages, cmm_timeout_seconds);
+		len = scnprintf(buf, sizeof(buf), "%ld %ld\n",
+				cmm_timeout_pages, cmm_timeout_seconds);
 		if (len > *lenp)
 			len = *lenp;
 		memcpy(buffer, buf, len);